Endocrine Abstracts

Objective: To determine whether people with an incidentally discovered adrenal mass are investigated according to regional and global standards (AACE guidelines); to determine the frequency of autonomous endocrine function.

Methods: We did a retrospective analysis of clinical, pathology, and radiology records from January 2007 to December 2011. Patients were included if they were seen in the outpatient clinic for evaluation of an adrenal mass >1 cm in size detected incidentally during radiological imaging for an unconnected problem between January 2007 and December 2011 inclusive.

Results: 63 patients met the inclusion criteria (62% females; mean age 63 (range 34–88) years). Investigations were completed with the following frequencies: overnight 1 mg dexamethasone suppression test 65%; 24 h urine free cortisol 57% (one of these two tests was performed in 92%); 0900 h ACTH 19%. U&E’s 97%; renin and aldosterone 87%; metanephrines or catecholamines 94%; DHEA, androstenedione or testosterone 76%; 17-hydroxyprogestrone 44%; oestradiol (men and post-menopausal women) 17%; CT assessment of adrenal attenuation and washout 84 and 5% respectively; appropriate follow-up imaging 78%.

21% patients had bilateral incidentalomas; in 90% of patients the final diagnosis was benign (in the remaining 10% the final diagnosis was not clearly recorded). In 24% patients autonomous adrenal hormone secretion was detected. Of autonomously secreting adenomas 73% were cortisol-secreting (60% subclinical and 13% clinical Cushing’s), 20% were pheochromocytomas, and 7% were aldosterone-secreting. 11% patients underwent adrenal surgery.

Conclusion: In this large cohort 24% of adrenal incidentalomas showed autonomous hormone secretion. The frequency of autonomous cortisol secretion (18%) was higher than previous data but phaeochromocytoms (5%) and aldosterone-secreting adenomas (2%) were detected with similar frequencies to previous reports. No adrenal carcinomas were detected in this series.